Mayor Walter Veltroni, who was due to meet Aziz this morning before the Iraqi left Italy to return to Baghdad, delivered the news in a stern letter. “I’m writing to inform you that I find myself obliged to cancel our meeting,” Veltroni wrote, according to a copy of the letter.

“The reason is because of your refusal to answer a question posed to you by an Israeli journalist at a news conference held at the Foreign Press Association (on Friday),” it continued.

“Rome, Mr deputy prime minister, has always had absolute respect for dialogue and the civil exchange of ideas, not to mention, obviously, freedom of opinion and free access to information,” the centre-left mayor wrote.

“I cannot accept that a public figure like yourself, the representative of another country, can set a veto and discriminate against someone, denying them the right to express themselves, no matter what position they may represent.”

The Iraqi deputy Prime Minister came to Italy last Thursday and during a busy four-day stay held a high-profile meeting with Pope John Paul at the Vatican and prayed at the tomb of St Francis of Assisi on the same day that millions around the world marched for peace.

It was on Friday, after his meeting with the pope, that Aziz gave a news conference at the Foreign Press Association. For more than half an hour, he took questions from over a dozen journalists and gave fairly full answers.

But when a correspondent for Israeli newspaper Maariv stood up and asked whether, in the case of war, Iraq intended to attack Israel, Aziz responded: “When I came to this press conference, it was not in my agenda to answer questions by the Israeli media. Sorry.”

The response drew boos and hisses from some journalists and several walked out.

Later, another journalist asked the same question and Aziz answered: “We don’t have the means to attack anyone outside our territory.”

Veltroni closed his letter saying that if Iraq and its representatives could not adhere to the principles of liberty and democracy, “there can be no hope for your country, nor for a solution to the crisis in the Middle East, nor for the prospect of a more just and peaceful world”.